Well cementng apparatus



Aug. 2o, 1940.

' w. THoRNHlLL -WELL CEMENTING APPARATUS Filed NOV, 27, 1939 C W` 7710m/z ill.

INVENTOR M ulm ATTO

Patented Aug. 20, 1940 UNETED STATES PATENT ori-lcs WELL CEMENTNG APPARATUS Charles w. Thornhill, Houston, Tex. Application November 27, 1939, Serial No. 306,225

10 Claims. v

This invention relates to float collar, guide shoe, and cementing tool combinations, and more particularly to those for use onl the lower end and at spaced points above the lower end of an oil well casing for use inthe cementing operation, and is an improvement and extension of the invention disclosed in my previous application Serlal'No, 107,770, led October 27, 1936, and is a continuation-impart of said application.

In cementing oil wells it is customary to provide some device, such. as a plug with check valve means, on the bottom 4of the casing, to enable the liquid cement to be forced through the bottom of the casing and into the hole around the casing and at the same time prevent the back 'flow of the cement into the casing. An improved form of such a plug is disclosed in my above mentioned application, said plug hav-l ing means to permit cement, when desired, to be forced laterally from the casing into the hole, and also providing a means for forcing water through the bottom o f the plug to assist in the lowering of the casing. This device, however, provides means for laterally ejecting the cement from the casing at only one point on the length of the casing, whereas there are numerous cementing jobs in which it is expedient to introduce the cement at several points spaced from the end of the casing. This is caused by irregularities in the hole, differences in strata, necessity for cementing oi water at a certain depth, etc. As far as I am aware, no one has evolved a device for accomplishing this operation by the means embodied in my invention.

The primary object of my invention is to increase the effectiveness of the operation of cementing oil wells.

Another object is a device for introducing cement laterally from the casing into the hole at a plurality of points spaced from its end.

Another o'bject is to improve the device disclosed in my above-identified application by providing means whereby a number of such devices may be operated one above the other, thereby producing'a more `effective cementing job.

These and other objects may be accomplished by my invention, which embodies among its features a casing and a plurality of cementing4 plugs, similar to the plug described in my previous application, arranged in the casing one above the other.

Further objects and features will become evident from the following disclosure when taken in' conjunction with the accompanying drawing, in which- Fig. l is a longitudinal cross-section through the bottom of a casing embodying my invention;

Fig. 2 is a longitudinal cross-section .of one of the plugs shown in Fig. 1, showing the sleeve in upper or duct-closing position; and,

Fig. 3 is a longitudinal cross-section of the device shown in Fig. 2, taken on a plane` at right angles thereto, and showing the sleeve in lower position, leaving the ducts open.

The plug structure which is similar to that shown in my previous application is shown in Figs. 2 and 3, and consists of a casing I.I containing a check valve plug I2 having a; bore I3 which seats a ball valve I4 supported by prongs I5. The ball valve will close to the broken line position shown in Fig. 2 to prevent any back flow through this plug.. Below this plug there is a cementing plug I6 having a bore I1 with an enlarged portion I8 having a liner I9. S-lidably mounted in the liner is a sleeve 20 with bore 2I smaller in diameter than bore I3. Frangible pins 22 hold the sleeve normally in upward position as shown in Fig. 2 so it closes the inner end of cement feeding ducts 23 which extend through the plug I6 and the casing. A ball 24 may be dropped into ,the device when it is `desired to feed cementlaterally through the ducts 23, this ball being smaller in diameter than bore I3 and larger than sleeve bore 2|, so that it will be carried by the flow of liquid through duct I3 until it seats in said sleeve' duct, to push the sleeve downwardly, breaking pins 22, into the position shown in Fig. 3 whereupon the ow through bore I'I is cut off and ducts 23 are opened. Accordingly it will be seen that the casing may be lowered into the drill hole with the sleeve 20 in upper position, andthe check valve structure I2, I3, I4 will prevent any flow of water or drill fluid into the casing while at the same time, if desired, water may be pumped through bore I1 to wash away any obstructions in the hole. 'When the casing is in position, the ball 24 is dropped into the casing and it nds its way into bore 2l, forcing down the sleeve. Then cement may be run into the hole surrounding the casing, it being ejected laterally through ducts 23. It

is to be understood that the entire plug structureV is made of cement or some friable material which may be drilled out when the cementing process I is completed.

The present invention .contemplates modifying and multiplying my previous invention so as to check valve plugs I2a, I2b, and I2c and cement- I ing plugs |6a, |621, and Hic. These are identical but smaller than I3a.

in structure and operation with the combination shown in Figs. 2 and.3, and described above, with the exception of the relative sizes of the bores and balls, as will be explained hereinafter.

Ball 24a is larger in diameter than bore 2Ia, Ball 2lb is larger than bore 2Ib, but smaller than I3a, and likewise ball 24e is larger than 2ic,butsmaller than I3c. It will therefore be evident that ball 24a will go through all bores except Zia, and the other balls will go .through all bores above the sleeve bore in which they are sized vto seat. Therefore, any one of the sleeves 20a, 20h or 20c may be operated at will by dropping the proper sized ball in the casing.

In operation, the casing containing the device is lowered into the drill hole, with the sleeves 20a, 20h and 20c in upper or inoperative position. The bores are therefore free to provide a passage for water to wash away any bridges or other obstructions that may occur in the drill hole. When the casing is at thedesired depth, and the cementing operation is to take place, ball 24a is dropped into the casing. and the flow of fluid,

f or gravity, will cause it to seat in bore 2!a of lso sleeve 20a; Further pressure will cause this sleeve to slide downwardlyI opening` its corresponding ducts and permitting the cement to ow laterally into the hole from the casing, without raising the casing olf bottom or otherwise disturbing its position. When this lower portion is completed, the next higher portion may be cemented by dropping in ball 24h, which operates sleeve 20h in identical manner. In this way the hole may be cemented from progressively higher points, thereby necessitating considerably less pressurevon the cement and accomplishing a rmer job. When 'the cement has set the plug structure may be drilled out.

It willbe understood that lin the cementing operation measured quantities of cement will be pumped for each stage and followed by a measured quantity of mud or other liquid, so that when the cement has set the casing will not be full of cement but will only have a relatively short cement plug adjacent the point of cementing. It will also be understood that the respective balls for causing the opening of the respective cement"I openings will not be dropped into a column of static mud standing in the well but that they will be pumped in. To this end, the balls for each of the upper stages will be dropped into the stream pf liquid going into the well after the cement for the previous stage is all in the well and mud is being pumped in after it.' A quantity of mud will be pumped in after the previous charge 4of cement, this quantity depending upon the distance between the respective cement openings, and then the ball for the next stage will be dropped in. .By virtue of this arrangement, the ball for the next succeeding stage will seat justr before the last ofthe cement is squeezed out through the cement openings of the last preceding stage.

It is to be noted that any number of plug organizations may be used, and they may be placed any desired distance apart. I do not Wish to be limited to the specic embodiment shown herein, but only by the scope of the appended claims.

I claimz.

l. In combination, a casing guide shoe having axial and late ral openings therein, means initially closing said lateral opening and movable by pressure within the casing when said axial opening is closed, a float collar above said shoe hav-I ing a passageway therein larger than the axial opening in said shoe, a downwardly opening check valve movable to fully open said passageway, an element above said iioat collar being similar in structure to said guide shoe, the axial opening of said element being larger than the passageway of said guide shoe, an additional element above said element being similar in structure to said float collar and having a passageway larger than that of said first element, and a valve element adapted to be passed down through all said passageways to close the axial opening in said shoe.

2. In combination, a casing guide shoe having axial and lateral openings therein, means initially closing said lateral opening and movable by l pressure within the casing when said axial opening is closed, a float collar above said shoe having a passageway therein larger than the axial opening in said shoe, a check valve in said passageway, an element above said float collar being similar in structure to said guide shoe, the axial vpressure within the casing when said axial opening is closed, a oat collar above said shoe having a passageway therein larger tha'n the axial opening in said shoe, a downwardly opening check valve in said passageway movable to fully open said passageway, an element above said float collar being similar in structure to said guide shoe, the axial opening in said element being larger thanthe passageway of said guide shoe, an additional element above said element being similar in structure to said oat collar and having a passageway larger than that of the first element, a valve element adapted to be passed down through all said passageways to'close the axial opening in said-shoe, and a second valve element adapted tobe passed through the passageway of the second element to close the passageway of the first element.

4. In a device of the class described, a casing,

' a plurality of cement-distributing elements in said casing having axial and lateral passageways and means whereby the lateral passageways are opened when their axial passageways are closed,

a plurality of check valve elements having passageways and alternating inthe casing with the cement distributing elements, the passageway of each element being larger than that of the element below it, vand a plurality of valve elements each adapted to close the passageways of a distributing element after having passed through the passageways above it.

5. In a well cementing device, in combination, apipe, a plurality of check valves in said pipe spaced one above the other for preventing upliow therethrough, said pipe having a cement opening therein below each of said check valves, means normally closing each cf said cement openings, and means movable downwardly past said respecadjacent thereto.

, most passageway being of a larger diameter than A tive check valves for selectively and individually opening saidvarious cement openings.

6. In a well cementing device, in combination, a pipe, a plurality of check valves in said pipe spaced one above the other for preventing upflow therethrough, said pipe having a lateral cement opening therein below each of said check valves, means normally closing each of said cement openings, and means movable downwardly past said respective check valves for selectively and individually opening said various cement openmgs.

7; In a well eementing device, in combination, a pipe, a plurality of check valves in said pipe for preventing -upow therethrough, said pipe having a longitudinal opening therethrough and having a lateral cement opening therein below each of said check valves, means normally closing each of said cement openings, and means movable past said respective check valves for selectively and individually opening said cement 'openings and for closing said longitudinal opening at a point 8. In a well cementing device, in combination, a pipe, a plurality of check vvalves in said pipe, one above the other, for preventing upflow therethrough, said pipe having a lateral cement opening therein below each of said check valves, means normally closing each of said cement openings and having a longitudinal passageway therethrough to conduct liquid past said lateral openings, each of said passageways above the lowerthe next lower'passageway, and means for selectively and individually opening said lateral openings and closing the longitudinal passageway adjacent thereto, each of said means being movable through the check valves and longitudinal passageways above-the lateral opening which it is adapted to open and being of a size incapable of passing through the longitudinal passageway adjacent the cement opening which lit is adapted to open.

9. In a well cementing device, in combination, a pipe, two check valves in said pipe, one above the other, for preventing upfiow therethrough, said pipe having a lateral cement opening therein below each of said check valves, means normally.

closing each of said cement openings and having a longitudinal passageway therethrough to conduct liquid past said lateral openings, the passageway through the upper of said members being larger than the passageway through the lower of said members, means movable through the longitudinal passageway in the upper of said members and through said check valves for opening the lower of said cement openings and closing the central passageway adjacent thereto, and means movable through the upper of said check valves for opening the upper of said cement openings and closing the longitudinal passageway adjacent thereto.

10. In a well cementing device, in combination, a pipe, a plurality of check valves in said pipe for preventing upflow therethrough, said pipe having a longitudinal opening therethrough and having a lateral cement opening therein below each of said check valves, a plurality of annular members within said pipe, said members normally overlying said lateral cement openings respectively, to close the same while leaving said longitudinal opening free for flow, and said annular members being individually movable downwardly to open said cement openings respectively, said annular members having openings therethrough of diierent sizes respectively, the member having the smallest size openings being at the lowermost end and the member having thel largest size opening being placed uppermost, and means movable past said respective check valvs for selectively and individually closing said annular members whereby pressure within said pipe will move said means and said annular members selectively and individually downwardly to open said respective cement openings.

CHARLES W. THORNHILL. 

